Add tools/hex/hex-color-average.c

tools/hex/hex-color-average.c

@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int hexval(int c)
+{
+	int ret = -1;
+	switch (c) {
+	case '0'...'9':
+		ret = c - '0';
+		break;
+	case 'a'...'f':
+		ret = c - 'a' + 10;
+		break;
+	case 'A'...'F':
+		ret = c - 'A' + 10;
+		break;
+	}
+	return ret;
+}
+
+int hex2dec(const char *hexstring)
+{
+	int value = 0, pos = 0, hex;
+	while ((hex = hexval(hexstring[pos++])) != -1)
+		value = (value << 4) + hex;
+	return value;
+}
+
+void usage(const char *command)
+{
+	printf("Usage: %s <rrggbb> <rrggbb>\n", command);
+	exit(1);
+}
+int main(int argc, char **argv)
+{
+	double col[6] = { 0 };
+
+	if (argc < 3)
+		usage(argv[0]);
+
+	for (int j = 1; j < argc; j++) {
+		int len = strlen(argv[j]);
+		for (int i = 0; i < len / 2; i++) {
+			char buf[3] = { 0 };
+			buf[0] = argv[j][i * 2];
+			buf[1] = argv[j][i * 2 + 1];
+			col[(j - 1) * 3 + i] = hex2dec(buf) / 255.0;
+		}
+	}
+	printf("[%s] { %.2f, %.2f, %.2f }\n", argv[1], col[0], col[1], col[2]);
+	printf("[%s] { %.2f, %.2f, %.2f }\n", argv[2], col[3], col[4], col[5]);
+	printf("[ mean ] { %.2f, %.2f, %.2f }\n",
+	       (col[0] + col[3]) / 2.0,
+	       (col[1] + col[4]) / 2.0,
+	       (col[2] + col[5]) / 2.0);
+}
+